typical usage).

PagePainter:
  Added 2 convenience methods for performing fast cropping and scaling
  from qpixmaps to qimages. Split buffered graphic flow from the unbuffered
  one reducing buffers conversions to the minimum. Avoid odd cases in
  rescaling. Detection of annotations boundaries to check for enabling
  buffered painting.
  Sample quick dirty and broken (but not so much..) implementation for
  painting AStamp annotations.
Misc:
  PresentationWidged and ThumbnailWidget: adapted to PagePainter changes.
  (PageView mod has already been committed).

svn path=/branches/kpdf_annotations/kdegraphics/kpdf/; revision=400310